Should my "adb backup" include the system files or not if I'm planning to downgrade my Android version?
I'm using Oneplus 3t on the latest Android 9 OS. I'm planning to downgrade it to Android 8 and hence backing up my data with adb first.
adb backup "-apk -obb -shared -all -nosystem -f d:/other backup/phoneadbbackup/backup2.ab
Now here's the problem. I could backup system apps as well. But I'm not sure whether or not that is a good idea.
After I downgrade, there's a chance that the system apps would remain the same. If yes, then that's great because all the data could get restored back for the system apps. However, if there are a few system apps missing in 8 then could that error out the restore process? If the apps are same but the data was different in 8 then restoring data from 9 would cause errors, isn't it?
So my question is:
- What does "-system" back up exactly?
- If I'm planning to downgrade my OS then does the above command look good?